Touchscreens are used for interfaces for electronic displays that can detect the location of an object which touches the display area. The object that touches the display surface is usually a finger, but other objects such as a stylus may be used. Touchscreens are found in laptop computers, tablet computers, and smartphones. The touchscreen eliminates the need for a pointer and in some cases, eliminates the need for a keyboard.
Touchscreens require a two-dimensional film with relatively high transparency and high conductivity. Methods of making touchscreens include providing a layer of Indium Tin Oxide (ITO) or alternatively a grid of thin metal traces. Both processes have drawbacks associated with them including high cost. ITO touchscreens, for example, are not conductive enough and require extensive electronics for large displays. The thin metal traces used in making a grid are typically patterned lithographically, which is slow and expensive.
It is desirable to provide a conductive grid with high transparency that is suitable for use in capacitive touchscreens. The grid lines should be sufficiently narrow so that they are not visible under normal viewing conditions. It is also desirable to provide a grid that does not require lithographic printing and is highly conductive.